Photographic compositions and processes

ABSTRACT

Photographic compositions including a radiation-sensitive complex of a triorganophosphine, e.g. a triarylphosphine, with an organoazide such as an arylazide are radiation-sensitive and can be imagewise exposed to activating rays to yield a species that can react with a dye-forming coupler to form an image dye, e.g. an azo dye. Optionally, such compositions can include a polymeric binder and/or a dye-forming coupler. In another aspect, imageforming compositions are presented which include the organoazide and a precursor to the triorganophosphine, a phosphonium salt for example, that yields triorganophosphine on treatment with base. With such an embodiment, the composition is relatively lightinsensitive prior to alkaline treatment which activates the composition by forming the phosphine-azide complex in situ, and shelf life is desirably extended. When these compositions are present on a support, photographic or image-forming elements are formed. Once the azide-phosphine complex is present in a composition or element of this invention, imagewise exposure to activating rays for the complex and subsequent or concomitant treatment with a dye-forming coupler or the like produces a photographic image in exposed regions, i.e., a negative image of the original exposure. If a leuco compound, dye forming coupler, etc., is present in the composition, then a visible image generally forms on exposure. After production of the image, it can be stabilized by overall heating. In certain cases, heat fixation also produces intensification of a low density or substantially latent photographic image. If desired, positive images can be formed by thermophotographic means. Once the phosphineazide complex is present in the composition, imagewise exposure to heat desensitizes the complex in heated regions and a subsequent overall exposure to activating rays for the complex produces either a visible or an intensifiable photographic image. No heat fixation is required, but image intensification can be accomplished by heat. Lithographic printing surfaces can be prepared when a hydrophilic polymeric azide is used to form the phosphine azide complex or when hydrophilic polymeric couplers are used to form the dye image.

United States Patent [191 Grisdale et al.

[111 3,856,531 [451 Dec. 24, 1974 [5 1 PHOTOGRAPHIC COMPOSITIONS ANDPROCESSES [75] Inventors: Patrick J. Grisdale; Bruce E. Babb,

both of Rochester, N.Y.

[73] Assignee: Eastman Kodak Company,

Rochester, N.Y.

22 Filed: June 4,1973 21 Appl. No.: 366,884

Related US. Application Data [62] Division of Ser. No. 168,392, Aug. 2,1971, Pat. No.

[52] U.S.Cl 96/91 N, 96/33, 96/35.1, 96/36.49, 96/75, 96/90 R, 96/115 R,

[51] Int. Cl. G03c 1/52, G03c l/58, G03c 1/72 [58] Field of Search..96/91 N, 90 R, 115 R, 115 P, 96/75, 33, 35.1, 36; 260/349 OTHERPUBLICATIONS Van Allan et al., Journal of Heterocyclic Chemistry, Vol.5, 1968, p.471-476.

Leffler et al., Journal of Organic Chemistry, Vol. 26,1961, p. 48104814.

Primary Examiner-Charles L. Bowers, Jr. Attorney, Agent, or FirmD. M.Schmidt [57] ABSTRACT Photographic compositions including aradiationsensitive complex of a triorganoph-osphine, e.g. atriarylphosphine, with an organoazide such as an arylazide areradiation-sensitive and can be imagewise exposed to activating rays toyield a species that can react with a dye-forming coupler to form animage dye, e.g. an azo dye. Optionally, such compositions can include apolymeric binder and/or a dye-forming coupler. In another aspect,image-forming compositions are presented which include the organoazideand a precursor to the triorganophosphine, a phosphonium salt forexample, that yields triorganophosphine on treatment with base. Withsuch an embodiment, the composition is relatively light-insensitiveprior to alkaline treatment which activates the composition by formingthe phosphine-azide complex in situ, and shelf life is desirablyextended. When these compositions are present on a support, photographicor imageforming elements are formed. Once the azidephosphine complex ispresent in a composition or element of this invention, imagewiseexposure to activating rays for the complex and subsequent orconcomitant treatment with a dye-forming coupler or the like produces aphotographic image in exposed regions, i.e., a negative image of theoriginal exposure. If a leuco compound, dye forming coupler, etc., ispresent in the composition, then a visible image generally forms onexposure. After production of the image, it can be stabilized by overallheating. In certain cases, heat fixation also produces intensificationof a low density or substantially latent photographic image. If desired,positive images can be formed by thermophotographic means. Once thephosphineazide complex is present in the composition, i'magewiseexposure to heat desensitizes the complex in heated regions and asubsequent overall exposure to activating rays for the complex produceseither a visible or an intensifiable photographic image. No heatfixation is required, but image intensification can be accomplished byheat. Lithographic printing surfaces can be prepared when a hydrophilicpolymeric azide is used to form the phosphine azide complex or whenhydrophilic polymeric couplers are used to form the dye image.

6 Claims, No Drawings PHOTOGRAPHIC COMPOSITIONS AND PROCESSES This is adivision of application Ser. No. 168,392, filed Aug. 2,1971, now US.Pat. No. 3,767,409.

BACKGROUND OF THE INVENTION 1. Field of the Invention This inventionrelates to photography and particu larly to new photographic andimage-forming compositions and elements that can be negative-working, aswell as to photographic processes that are useful in pro ducing stableimages that can be formed in the substantial absence of moisture ornoxious developing agents.

2. Description of the Prior Art Photographic compositions designed fordry or substantially dry processing are known. Widely used suchformulations are two-component diazotype compositions that include adiazonium salt and a coupler that, under alkaline conditions, can reactwith the diazonium salt to form an azo dye. A broad description ofdiazotype elements appears in Kosar, Light-Sensitive Systems, John Wiley& Sons, Inc., New York (1965), especially at Chapter 6. On exposure tolight, the lightsensitive diazonium salt is destroyed and subsequenttreatment with an alkaline developer like ammonia promotes a dye-formingreaction in unexposed areas to produce a positive reproduction of anoriginal line transparency or the like. Diazotype-compositions, however,have certain disadvantages in that they tend to suffer backgroundprintup on storage. This tendency can be diminished by inclusion of anacidic precoupling inhibitor, but the addition of such a material slowsdevelopment rate since the inhibitor must be neu tralized beforecoupling can occur. Additionally, well known developing agents likeammonia are generally either toxic and/or noxious.

Another type of diazotype photographic element uses diazosulfonateswhich, on exposure to light, form diazonium salts that can couple in thenormal fashion. These elements are negative-working since they produceimage dye in regions of exposure. However, they suffer the disadvantagethat image stabilization usually requires a washout step to removeremaining sensitive components.

Still another well-known type of negative-working photographic elementuses organic azides and dye precursors. See, for example, US. Pat. No.3,062,650. Such elements yield a printout image directly on exposure.However, an inconvenient washout step to remove unreacted components isgenerally necessary to stabilize background areas against subsequentprintout.

The desirability of providing new photographic elements that do not usesilver as the light-sensitive agent (it being in short supply) and thatproduce stable images without substantial moisture, stabilizationwashes, or noxious or toxic developing agent is widely acknowledged.Additionally, widespread contemporary apprehension relative to organicpollutants and their effect on the environment has stimulated activitydesigned to inhibit the flow of contaminants into the environment. Suchgoals are also of deep concern to those skilled in the photographicarts.

Accordingly, it is an object of this invention to provide newphotographic compositions.

It is another object of this invention to provide novel photographiccompositions including a radiationsensitive complex of atriorganophosphine with an organoazide.

Still another object of the present invention is to provide new imageforming compositions that include an organoazide and atriorganophosphine precursor.

Yet an additional object of the instant invention is to provide novelphotographic .and image-forming ele ments that include the presentphotographic and image-forming compositions.

Another object of this invention is to provide new photographicprocesses for preparing stable images.

An additional object of this invention is to provide novel photographicprocesses for preparing stable images by means of light and heat in thesubstantial absence of moisture.

Still another object of this invention is to provide newthermophotographic processes for preparing stable images. I

STATEMENT OF THE INVENTION The objects of this invention are:accomplished, with radiation-sensitive phosphineazide complexes. In oneaspect, the invention relates to new photographic compositions thatinclude a radiation-sensitive complex of a triorganophosphine withanorganoazide'. In another aspect, the present invention includes novelimageforming compositions containing suitable precursors to thelight-sensitive complex and from which the aforementioned complex can bereleased conveniently. Optionally, such photographic and image-formingcompositions can include a dye precursor, e.g. a dye-forming coupler.

The photographic compositions yield an image directly on exposure toactivating radiation for the complex. No external processing agents arerequired. The

background regions can then be stabilized against printup by simple heatfixation. In certain cases, this heating step also produces anintensification of the image. As used herein, the term photographicimage refers to visible and latent photographic images. Theimage-forming compositionscan be exposed and developed with similarconvenience, but require liberation of the radiation-sensitive complexfrom the precursors prior to exposure. This can be done, for example, bycontacting the image-forming composition with base. Additionally, .if aparticular photographic or image forming composition or element does notcontain a coupler, exposure is advantageously followed by treatment witha coupler solution. If desired, positive images can be prepared bythermophotographic means, using an imagewise thermal exposure followedby an overall exposure to activating radiation for the complex (i.e.radiation to which the phosphineazide complex is sensitive). Heatfixation is not required but heating can be used to effect imageintensification if desired. Additionally, where the azide of the complexis a polymeric azide or where the coupler is a polymeric coupler,lithographic surfaces can be prepared.

DESCRIPTION OF PREFERRED EMBODIMENT(S) In accordance with the presentinvention, there are presented new photographic compositions includingradiation-sensitive complexes of a triorganophosphine with anorganoazide. As used herein, the term radiation sensitive describedsensitivity to electromagnetic rays including X-rays, ultraviolet rays,visible light and the like. The phosphine-azide complexes describedherein are chemical complexes that; on exposure to activating rays forthe complex, yield a species that can react with a coupler to form animage dye.

A wide variety of triorganophosphines (i.e. phosphines having threeorganic chemical substituent groups) are useful in formingradiation-sensitive complexes of the present type. In general, anytriorganophosphine that will form such a complex with an organoazide isuseful. Determination of such utility can be accomplished convenientlyby simple screening. For example, any triorganophosphine can becodissolved with an organoazide of the types recited elsewhere herein(i.e. p-morpholinophenylazide and/or 4- azidobenzenesulfonamide) usuallyin equivalent molar quantities or with a slight excess of phosphine andwith a fi-naphthol dye-forming coupler, e.g. 2-naphthol, 2,3-naphthalenediol, etc., to form a solution which can be coated onto asupport, dried in a layer and thereafter exposed to activating radiation(i.e. rays to which the complex is sensitive) to form a photographicimage which is visible or is intensifiable to a visible image. If thisimage, when visible, is different in color and/or intensity from thephotographic image that is formed wherein:

each of R, R and R independently represents one of either an alkyl groupand preferably lower alkyl, an alkoxy group and preferably lower alkoxy,an aryl group and preferably phenyl, or an amino group having theformula wherein:

R represents one of either an alkyl group or an aryl group, and Radditionally represents a group having the formula wherein:

n represents a positive integer having a value of from 1 to about 18 andeach of R and R is as previously defined.

As used herein the term alkyl group includes substituted orunsubstituted, straight and branched chain alkyl groups having from 1 toabout 8 carbon atoms in the aliphatic chain used as a basis forestablishing the nomenclature for such group. Representative alkylgroups include. for example methyl groups, ethyl groups, 2-chlorocthylgroups, n-propyl groups, isopropyl groups, n-butyl groups, tert-butylgroups, pentyl groups. hexyl groups, heptyl groups, n-octyl groups,tert-octyl groups, etc. The term alkoxy group as herein defined,includes alkoxy groups the alkyl moiety of which has from 1 to about 8carbon atoms and corresponds to the alkyl groups recited immediatelyhereinabove. The term lower alkyl group or lower alkoxy group refers tosuch alkyl or alkoxy groups having from 1 to 4 carbon atoms in thealiphatic chain used as a basis for establishing the chemicalnomenclature for any such group.

Aryl group, as herein defined, includes substituted or unsubstitutedmono and polycyclic aromatized carbocyclic groups having, from 6 to 14atoms in the nucleus, e.g., phenyl, p-chlorophenyl, 4-methylphenyl,naphthyl, anthryl, etc., with phenyl being preferred.

Especially desirable triorganophosphine compounds includetriphenylphosphine tris(3-methylphenyl)phosphineP,P-diphenyl-P-methylphosphine tris(4-methylphenyl)phosphinetrimethylphosphine P,P-diphenyl-P-ethoxyphosphineP,P-dimethyl-P-phenylphosphine P-pentafluorophenyl-P,P-diphenylphosphinebutyldimethoxyphosphine tris(n-butyl)phosphinetris(dimethylamino)phosphine tris(n-octyl)phosphinetris(diphenylamino)phosphine P-methyl-P,P-diphenylphosphinetris(4-chlorophenyl)phosphine tris(4-methoxyphenyl)phosphinetriethoxyphosphine l,2-bis(diphenylphosphino)ethanel,4-bis(di-n-butylphosphino)butanel,8-bis(di-4-chlorophenylphosphino)octane According to this invention,at least one triorganophosphine is chemically combined with anorganoazide to form radiation-sensitive phosphine-azide complexes. Suchcomplexes form under ambient conditions when the triorganophosphine andorganoazide are brought into intimate contact such as by codissolvingthem in a suitable solvent. As with the triorganophosphine, a wide rangeof organoazides are useful, and the operability of any particular azidecan be established by the convenient procedure outlined hereinabove withrespect to the screening of triorganophosphines. In this instance,however, an operator would codissolve the azide in question with aphosphine that is known to operate in the present compositions, elementsand processes, e.g. triphenylphosphine.

Desirable organoazides (i.e. organic azides) include a large variety ofradiation-sensitive compounds that have been used heretofore inphotographic printout compositions of the type that includes the azideand a dye-former that reactswith the azide upon exposure to activatingrays to form a dye in exposed regions. Certain such azides include mostof the aryl azides, aminoarylazides, and heterocyclyl azides describedin U.S. Pat. No. 3,062,650 and U.S. Pat/No. 3,282,693. Azides useful asphotosensitizers for polymers are also useful herein. Suchphotosensitizers can be the same as or different from the azides usefulin printoutmaterials and they are described in some detail in Kosar,Light- Sensitive Systems," John Wiley & Sons, Inc, New York 1965)especially at pp 330-336 (including footnotes). Still other descriptionsof useful organic azides appear in U.S. Pat. Nos. 2,940,853; 3,061 ,435,and 3,143,417. With regard to heterocyclyl azides, it is preferred thatthe azido group is not substituted on the heterocylic ring at a positionortho to a hetero ring atom. Other advantageous azides include polymericazides such as those described in US. Pat. Nos.

3,002,003 and 3,096,311.

Particularly useful organoazides include such materials as thefollowing;

4-azidobenzenesulfonamide ethyl 4-azidobenzoate ethyl 2-azidobenzoate4-azidobenzoate 3-azidobenzoic acid 4-azidobenzenearsonic acid4-azidobenzamide 4-azido-N-methylacetanilide 4-azidobenzophenone2-(4-azidophenyl)-6-methylbenzothiazole 3-azido-a,a,a-trifluorotoluene3-azido-4-chloro-a,a,a,-trifluorotoluene 4-azidobenzonitrile3-hydroxypropyl 4-azidobenzoate phenyl 4-azidobenzoate2-(3-hydroxynaphthyl)4-azidobenzoate 4-methyl-N-phenyl-4-azidobenzamideN-( 2,6-dimethylphenyl)-4-azidobenzamide 4-azidobenzopiperidide N-(l-naphthyl)-4-azidobenzamide N-(pentatluorophenyl)-4-azidobenzamidephenyl 4-azidophenylsulfonate 2,4,6-trichlorophenyl4-azidophenylsulfonate N-(4-azidophenylsulfonyl)phthalimide4-azidobenzophthalimide N-phenyl-N-methyl-4-azidophenylsulfonamideN-(4-azidophenylsulfonyl)-piperidineN-(2,6-dimethylphenyl)-4-azidophenylsulfonamideN-(4-azidophenylsulfonyl)succinimideN-(6-azido-2-naphthylsulfonyl)piperidineN-methyl-N-phenyl-2-azidonaphthalene-6- sulfonamide phenyl6-azidonaphthalene-2sulfonate N-(6-azido-Z-naphthylsulfonyl)succinimideN-(6-azido-2-naphthylsulfonyl)phthalimide l-azido-2,4,6-trichlorobenzene2-azido-3-nitrobenzene 4-azidobenzoic acid 3-azidophthalic anhydride4-azidocinnamic acid 3-azidobenzenesulfonamide 2-azido-9-fluorenonel-azido-5-methoxynaphthalene 2-(4-azidophenyl)-5-phenyloxazole4'-azido-4-chlorochalcone 2-(4-azidophenyl)benzoxazolel-azidonaphthalene 2-phenyl-5-(4-azidophenyl)oxazole2-(4-azidobenzylidene)-3,4-dihydro-2H-1- naphthone 4-azidochalcone IN-(4-azidobenzylidene)-4-chloroaniline 2-(4-azidophenyl)benzimidazolel-azido-2,4-dichlorobenzene 2-(3*azidophenyl)-5-phenyloxazole4,4'-diazido-3,3'-dimethoxybiphenyl 2-azidophenetole 4-azidophenetoletrimethylene bis(4-azidobenzoate) bis(4azidophenyl)disulfide b4-azido-3,S-diethoxybenzanilide: N-methyl-4-azidoacetanilide4-azidophenyl sulfide 4-azido-3-nitroanisoleN-(3-azidophenylsulfonyl)succinimide4-azido-3,5-dimethoxyphenylmorpholine 3-azidoquinoline Z-azidocarbazole2-azidobenzoic acid 4-azidophenoxyacetic acidN-methyl-N-octadecyl-4-azidoaniline l azido-4-bromonaphthalenebis(4-azidophenyl)ether 4-azidoazobenzeneN-(4-azidophenyl)-N-methylmo:rpholinium tetrafluoroborate 4-azido4-toluenesulfonanilide 4-azidobenzenesulfonic acidl-azido-4-methoxynaphthalene 4-azidostyryl l-naphthyl ketone3-(4-azidophenyl)coumarin l,2,3,4,5,6,-hexa(4-azidobenzoxy)hexane4,4-diazidodibenzalacetone 1azido-2,4,6-tribromobenzene4-azidoacetanilide 2-azidodiphenyl ether 2,5-bis(4-azidophenyl)oxazole2-(4-azidophenethyl)-5-phenylo:xazole 2-(4-azidophenethyl)benzoxazole4,4'-diazido-2,2-stilbenedi(N,N-dibutylsulfonamide2,6-di(4azidobenzal)-4-methylcy'clohexanone poly(vinylacetate-co-4-azidobenzoate) l-azido-3-cyano-4-methoxybenzenel-azido-3-cyano-4-morpholinobenzene N-(4azido-2-cyanophenyl)piperidineN-butyl -4-azido-2-cyanoaniline N,N-diethyl'4-a2ido-2-cyanoanilineN,N-dibutyl-4-azido-Z-cyanoanilineN'-hydroxyethyl-4-azido-2-cyanoanilineN,N-diethyl-4-azido-2-chloroaniline 4-azidodiphenylamine4-azido-Z-cyanodiphenylamine 4-azido-2-cyano-4'-methoxydiphenylamine4-azido-2-cyano-4-dimethylaminodiphenylamine1-azido-2-methoxy-4-morpholinobenzenel-azido-3-methoxy-4-morpholinobenzeneN-methyl-4-(4-azidophenyl)-2,6-diphenylpyridinium perchlorateN-methyl-4-(4-azidostyryl)-2,6diphenylpyridinium perchlorate, and2,5-bis-(4-azidophenyl) oxadiazole In another aspect of the presentinvention, the trimganophosphine can be replaced by a precursor for suchphosphine to prepare stable image forming compositions. Image-formingcompositions and elements of this invention are distinguished from thesubject photographic compositions and elements in that the imageformingcounterparts do not contain the radiationsensitive phosphine-azidecomplex as prepared, it being formed therein at a subsequent time asdesired. Especially desirable phosphine precursors are those which, onchemical treatment, e.g. on treatment with base,

yield a triorganophosphine that can form a radiationsensitive complexwith an azide such as those described herein. since theseimage-formingcompositions are not substantially radiation-sensitiveprior to liberation of the phosphine, their sensitivity being limited tothat of the low speed azide, they enjoy an extremely high storagestability. Once the phosphine is released, such as by means of chemicaltreatment, the radiation-sensitive phosphine-azide complex formsspontaneously in situ and the activated composition can be used toprepare photographic images according to the procedures describedherein.

A preferred class of phosphine precursors are phosphonium salts fromwhich the corresponding triorganophosphine is easily released bytreatment with base, e.g.

fuming with ammonia. A wide range of. useful phosphonium salts includethose described in a patent application of Reynolds entitledImage-Forming Compositions Including Phosphonium Salts, filedconcurrently as U.S. Ser. No. 168,395, now abandoned the completedisclosure of which is incorporated by reference. Exemplary phosphoniumsalts useful herein include cyclohexanon-3yltriphenylphosphoniumchloride 2-methylcyclohexanon-3-yltriphenylphosphonium tetrafluoroboratecyclohexanon-3-yltri-p-tolylphosphonium chloride2-methylcyclohexanon-3-yltri-p-tolylphosphonium perchlorate2-ethoxycarbonylethyltriphenylphosphonium tetrafluroborate2-ethoxycarbonylethyltri-p-tolylphosphonium bromide3-oxobutyltriphenylphosphonium tetrafluoroborate4-oxopent-2-yltriphenylphosphonium chloride3-oxo-l-phenylbutyltriphenylphosphonium perchlorate3-oxobutyltri-p-tolylphosphonium chloride4-oxopent-2-yltri-p-tolylphosphonium bromide 3-oxo-l-phenylbutyltri-ptolylphosphonium bromide a-benzoylmethylbenzyltriphenylphosphoniumtetrafluoroborate a-benzoylmethylbenzyltri-p-tolylphosphonium chlorideAnother preferred class of phosphine precursors from whichtriorganophosphine can be released by treatment with base are certainstable transition metal complexes of triorganophosphines. They aredescribed in detail in a patent application of Nelson entitled -ImageForming Compositions Including Transition Metal Complexes," filedconcurrently and now U.S. Pat. No. 3,764,335.

The photographic and image-forming compositions can, if desired, containa polymeric carrier vehicle. Advantageous carriers include film-forming,substantially hydrophobic polymers that can be coated using organicsolvents, but which are sufficiently permeable to bases including gassesand liquids so as not to restrain either convenient phosphine releasefrom a precursor or image dye development. Especially useful suchcarrier or binder vehicles include polymers like, for example,cellulosic compounds such as ethyl cellulose, butyl cellulose, as wellas cellulose esters like cellulose acetate, cellulose triacetate,cellulose butyrate, cellulose acetate butyrate, etc; vinyl polymers suchas poly(vinyl acetate), poly(vinylidene chloride), poly(vinyl butyral),copolymers of vinyl chloride and vinyl acetate, polystyrenes,poly(methyl methacrylate) homopolymers or copolymers of acrylamides,copolymers of alkylacrylates and acrylic acid, etc., such aspoly(N-isopropylacrylamide) poly(diacetone acrylamide) copoly(diacetoneacrylamide/N- isopropylacrylamide)copoly(methacrylamide/N-isopropylacrylamide)copoly(N-isopropylacrylamide/1-vinyl-2- pyrrolidone) copoly(methylmethacrylate/methacrylic acid) copoly(butyl acrylate/acrylic acid) aswell as additional polymers such as poly(phenylene oxides), terpolymersof ethylene glycol, isophthalic acid and terephthalic acid, terpolymersof pcyclohexanedicarboxylic acid, isophthalic acid andcyclohexylenebismethanol, copolymers of pcyclohexanedicarboxylic acidand 224,4-

tetramethylcyclobutane-l,3-diol, and additional polymers such as, forexample, the condensation product of epichlorohydrin and bisphenol-A.

The photographic or image-forming compositions of this invention canalso'include a dye-forming coupler which, it is theorized, reacts with aphotolytic product of the phosphine-azide complex to form a dye inexposed regions. If used, the coupler is usually present in a molaramount substantially equivalent to the amount of phosphine-azidecomplex, or in a slight excess, e.g. 5-10% molar, to insure maximum dyeformation.

Couplers that are advantageous herein include couplers of the type usedin two-component diazotype compositions. Such couplers are described inthe literature, for example in Kosar Light-Sensitive Systems,John Wiley& Sons, New York (1965), especially at pp 220-240. Especially desirablecouplers are recited in U.S. Pat. No. 3,573,052, especially at column.6, line 17 to column 7,line 20. Representative couplers of this typeinclude 2,3-naplithalene diol 2-hydroxy-3-naphthanilide2-hydroxy-2-methyl-3-naphthanilide 2-hydroxy-2',4-dimethoxy-5'-chloro-3-naphthanilide 2-hydroxy-2,4'-dimethoxy-3-naphthanilide2-hydroxy-2,5'-dimethoxy-4'-chloro-3- naphthanilide 2-hydroxy-l '-n aphthyl-3-naphthanilide 2-hydroxy-2'-naphthyl-3-naphthanilide2-hydroxy-4-ch loro-3-naphthanilide 2-hydroxy-3-naphthanilide2-hydroxy-2',5 -dimethoxy-3anaphthanilide2-hydroxy-2,4'-dimethyl-3-naphthanilide l-hydroxy-Z-naphthamideN-methyll -hydroxy-2-naphthamide N-butyl-l -hydroxy-2-naphthamideN-octadecyl- 1 -hydroxy-2-naphthamide N-phenyll -hydroxy-2-naphthamideN-methyl-N-phenyl-l-hydroxy-2-naphthamideN-(2-tetradecyloxyphenyl)-l-hydroxy-2- naphthamideN-[4-(2,4-di-tert-amylphenoxy)butyl]-lhyclroxy-2- naphthamidel-hydroxy-2-naphthopiperidideN-(3,S-dicarboxyphenyl)-N-ethyl-l-hydroxy-2- naphthamideN,N-dibenzyl-l-hydroxy-Z-naphthamideN-(2-chlorophenyl)-l-hydroxy-2-naphthamideN-(4-methoxyphenyl)-l-hydroxy-2-naphthamidel-hydroxy-2-naphthopiperizide l,3-bis( l -hydroxy-2-naphthamido)benzene2-acetamido-5-methylphenol Z-acetamido-S-pentadecylphenol2-butyramido-5-methylphenol 2-(2,4-di-tert-amylphenoxyacetamido)-5-methylphenol 2-benzamido-5-methylphenol Still other useful couplersinclude those which contain a reactive methylene or methine group, suchas those described in U.S. Pat. No. 3,062,650, especially at column 4,line 8 to column 4, linee 27. This type of coupler, e.g.3-methyl-l-phenyl-5-pyrazolone, is particularly useful when theorganoazide has an amino group substituted on the organic residue, as inthe case of an aminoarylazide. Preferably, such aminoarylazides are4-amino-l-azidobenzene compounds or derivatives.

The photographic compositions of this invention are convenientlyprepared, for example, by codissolving at least one triorganophosphineand at least one organoazide. Desirable solvents include a wide range oforganic media such as methyl ethyl ketone, methylene chloride, acetone,lower alkanols, dichloroethane, tetrahydrofuran, toluene, etc., eitheralone or in combination. In the solution, the ratio of phosphine toazide can be varied widely, but it is preferred that the phosphine beincluded in a slight molar excess, e.g. from 5-l0%, to in-' sure thatsubstantially all azide is complexed. Without substantially completeazide complexing background stabilization is impaired. Image-formingcompositions are prepared in a like manner except that the phosphineprecursor is included in lieu of the triorganophosphine.

Photographic and image-forming elements utilizing the photographic andimage-forming compositions of this invention are conveniently preparedby coating such compositions onto a support material. Advantageoussupport materials include conventional photographic film base materialslike cellulose esters such as cellulose acetate, cellulose triacetate,cellulose acetate butyrate, etc.; poly-a-olefins typically having from2to carbon atoms like polyethylene, polypropylene, and polystyrene;polyesters such as poly(ethylene terephthalate); polycarbonates as wellas metals such as zinc and aluminum and paper including polyethylene andpolypropylene coated papers. Other support materials that are suitablyused herein are known in the art.

Coating is typically by solvent coating means, since t off rs t e. qtenlfqtraizis .wn n snt Continuous operation. Coating is effected by firstdissolving components of the photographic or image-forming compositionin a suitable solvent, such as those described herein, along with amatrix polymer if desired. Exemplary matrix polymers are describedhereinabove. The coating solution conventionally contains from about 5to about 20 weight percent solids, and preferably from about 8 to aboutpercent solids. In that solution, if a matrix polymer is utilized, theimage-forming components are typically included in an amount of fromabout to about 50 parts of weight per 100 parts of polymeric binder,with concentrations in the range of from about to about parts per 100parts of matrix polymer eing preferred. Wider variations are possiblewhere desired, but the above-mentioned ratios are typical for mostconventional preparations. After coating by such means as immersion,whirler coating, brushing, doctor blade coating, hopper coating or thelike, typically at a wet thickness of from about 0.001 inches to about0.02 inches, the coated material is dried to prepare a compositephotographic or image-forming element of this invention. The subjectphotographic elements are radiation-sensitive and, without furthertreatment, can be imagewise exposed to activating rays for purposes ofimage preparation. The selection of appropriate exposing rays willdepend on the spectral response for the particular phosphine-azidecomplex. Characterization of appropriate exposing rays can be readilydetermined by preparation of wedge spectrograms for the phosphine-azidecomplex in question. Generally, however, the region of spectral responsewill include ultraviolet and other actinic rays so that exposure bymeans of a mercury arc lamp, which is rich in U.V. rays, or a similarexposure source is appropriate. Numerous diazo copiers and othercommercially available photocopying apparatus incorporate exposurestations which include radiation sources emitting in the U.V. As ageneral rule these are quite satisfactory for exposing compositions andelements of this invention.

It is noted that the radiation-sensitivity of the phosphine-azidecomplexes described herein should not be equated to the knownsensitivity of aryl azides such as those used in vesicular photographyor other photographic systems. Such compounds are known to exhibit lowphotoreactivity, whereas the radiation-sensitive complexes of thisinvention exhibit a relative photographic speed about ten times that ofa comparable non-complexed azide.

As noted herein, the subject image-forming compositions and elements areactivated to yield a triorganophosphine and form the phosphine-azidecomplex by chemical treatment including treatement with base. Generally,any of the bases useful :ln initiating coupling in diazotypereproduction media, eg. ammonia, organic amines and other organicnitrogen bases, are suitable herein to release the phosphine from itsprecursor. A range of such bases is described in Kosar, citedhereinabove, as well as in the patent literature, for example U.S. Pat.No. 3,578,452, Canadian Patent No. 772,109, etc. It is preferred thatthe base have a pH of at least about 8 so that activation is obtainedrapidly. Treatment can be accomplished by immersion in a solution of thebase, by fuming with vapors of the base, etc.

When the sensitive phosphine-azide complex of a photographic compositionor element or suitably activated image-forming composition or element isexposed to activating rays, and if a coupler is included in thecomposition or element that is so exposed, an image forms in exposedregions. Usually, this is a readily visible dye image which can vary inoptical density depending on the particular formulation. ln certaincases, the image may be a latent image that is not easily visible or isnot visible at all. It is theorized that the dyeforming reaction ispromoted by the imagewise release of hydroxyl ions and ammoniumhydroxide on exposure of the phosphine-azide complex. It is theorizedfurther that this liberation is due to reaction of a phosphinimine anionthat is formed on exposure with water that is inherently present in thecomposition or element.

Subsequent to an image-defining exposure, the composition or element ispreferably heated to a temperature sufficient to stabilize non-imageregions against printup (i.e. to stabilize the photographic image). Itis theorized that on heating, the phosphine-azide complex rearranges toform a stable, substantially colorless phosphinimine. Where the imageafter exposure either is of low optical density or is a latent image,the heat stabilization treatment simultaneously effects an imageintensification such that it is readily viewable by eye. Stabilizationheating is generally accomplished at temperatures of at least about 60C,with temperatures up to about 130C being useful for most situations. Itwill be recognized that the support or any components should not bedeliteriously affected by heating, but higher temperatures requireshorter fixation times. The duration of the heat fixing step isvariable, depending on factors like fixation temperature, etc. Usually,times of from about seconds to 2 minutes are sufficient. Heating'can becarried out conveniently, such as by contact with a suitably heatedsurface, insertion into a heated chamber or the like.

In cases where no coupler is present in the composition or element,exposure of the phosphine-azide complex is desirably followed bytreatment of the composition or element with one or more couplers of thetypes described herein to promote image formation. A dense dye imagewill then form spontaneously, or an intensifiable image of the typenoted herein will result. As an example of useful treatment methods, acoupler solution can be contacted against the composition or element bysuch means as immersing the composition or element therein, swabbing orspraying the solution over the composition or element, or by a similarmeans. After such treatment, the composition or element can be washedand/or dried or drying can be accomplished simultaneously with heatstabilization.

In one embodiment of the invention, a base can be included in animage-forming composition or element, in lieu of the phosphineprecursor. Useful bases include, for exampleN,N,N',N'-tetramethylethylene diamine, as well as a wide variety ofother organic amines and nitrogen containing organic compounds.Activation to form the phosphine-azide complex is then accomplished bytreatment with a phosphine precursor such as those described herein.Treatment is easily carried out by using a solution of the precursoraccording to methods like those discussed previously with reference tocoupler treatment.

In yet another embodiment of this invention, an image'formingcomposition that includes a phosphine precursor, a radiation-sensitiveazide of the type described in U.S. Pat. NO. 3,062,650wherein an aminogroup is present thereon, e.g. a p-disubstitutedaminophenylazide, and acoupler that is reactive with such an azide, multiple images such astwo-color dye images can be prepared as follows: The composition isgiven a first imagewise exposure with activating radiation for theazide, i.e., radiation to which the azide is sensitive. A visible dyeimage forms on exposure. The composition is then activated by chemicaltreatment such as by contact with base (eg by fuming with ammonia vapor)to release triorganophosphine from the precursor and form thephosphine-azide complex and thereafter is given a second imagewiseexposure with activating radiation for the complex, i.e., radiation towhich the complex is sensitive. Since the complex is a differentchemical species from the azide, it can have a different spectralabsorption envelope. Accordingly, each exposure may require the use of adifferent radiation source, although ultraviolet rays will generallysuf- I fice. On the second exposure, an image forms in exposed regions.It will be appreciated that this second dye image may, in certain cases,be intensifiable as discussed herein. This second image, when'visible,is preferably of a different color from the image formed on the firstexposure. Heat stabilization is then accomplished, and this also effectsimage intensification of the second dye image if it is of a low opticaldensity. If the concentration of azide is sufficient, and the firstexposure is not so intense that all azide is photolized in regions ofexposure, then remaining azide in such regions will complex with thephosphine on activation with base and the second exposure will produce asecond dye in areas that are common to each exposure.

As discussed previously, the compositions and elements of this inventionare useful in preparing negative images, i.e. images corresponding toregions of irradiation. They can also be processed by thermophotographictechniques to prepare positive images. i.e. images corresponding tonon-irradiated regions. A photographic composition or element, or animage-forming composition or element which has been activated to form aphosphine-azide complex therein, is given an imagewise thermal exposure-to stabilize such regions against printup. Thereafter, it is overallexposed to activating radiation for the complex to prepare a visible orintensifiable dye image. If no coupler is present in the element, imagedevelopment will also include treatment with a coupler solution asdescribed elsewhere herein.

In still another embodiment of this invention, lithographic surfaces areprepared in exposed regions when the azide used is a hydrophilicpolymeric azide like those described in U.S. Pat. No. 3,002,003 andother references cited therein. Lithographic surfaces can also beprepared when the coupler is a hydrophilic, polymeric coupler such as apolymeric pyrazolone. Desirably, the azide used with the polymericcoupler is a his azide. After exposure and subsequent process steps asdescribed herein, the developed surface is wet with water which isaccepted in unexposed areas. Greasy printing inks are transferable fromexposed regions which comprise the printing surface.

The following examples are included for a further understanding of theinvention.

EXAMPLE 1 A solution of l-azido-4-morpholinobenzene (0.2 g),4-methoxy-l-naphthol (0.2 g) and triphenylphosphine (0.25 g) is preparedin 20 ml of a 4% solution of poly(- vinyl butyral) in methyl ethylketone. This solution is whirl coated on aluminum and exposed imagewiseto the ultraviolet rich rays of a 250 Watt high pressure mercury vaporlamp, yielding a purple printout image. The unexposed areas are thenstabilized by heating the plates to C for 1 minute.

EXAMPLE 2 A solution of 4-azidobenzenesulfonamide (0.2 g),2,3-naphthalenediol (0.2 g), and cyclohexanon-3-yltriphenylphosphoniumchloride (1.0 6) in 30 ml of a 10% cellulose acetate butyrate solutionin methylene chloride is doctor blade coated at a thickness of 0.006inch on poly(ethylene terephthalate) support and dried. The resultantelement is then exposed to NH vapor. Thereafter, the image-formingelement is exposed through a silver negative at 20 ft./minute in theexposing unit of a Model 22,000 Ozalid machine marketed by OzalidCorporation. The machine contains a 1200 Watt high pressuremercury-vapor lamp as an exposure source. The resulting yellow-orangeimage is heated at C for 10 seconds to produce a stable, fixed print.

EXAMPLE3 A solution of l-azido-4-(2-benzimidazolyl)benzene (0.05 g)triphenylphosphine (0.10 g) and 4- methoxynaphthol (0.05 g) is pouredonto a filter paper and dried. The paper is then exposed imagewise to a500 Watt infrared lamp for 10 seconds through and in contact with asilver negative. The entire sheet is then irradiated with UV. light toproduce a dye image in the thermally unexposed areas.

EXAMPLE 4 A solution of p-morpholinophenyl azide (0.15 g), a coupler,2,4-dichloro-6-(2,4-dipentylphenoxyacetamido)-3 methylphenol (0.2 g) andP-(2-acetyll-phenylethyl)P,P,P-triphenylphosphonium tetrafluoroborate(0.8 g) is prepared in 15 ml of acetone. This is added to 15 ml of a 10percent solution of cellulose acetate butyrate in dichloroethane and themixture is doctor blade coated on poly(ethylene terephthalate) filmsupport at a wet thickness of 0.006 inch. The resulting image-formingelement is first exposed on a Model 22,000 Ozalid machine at ft./minuteto form a blue dye image in exposed areas. The element is then contactedwith moist ammonia vapor at 50C for seconds to liberate phosphine fromthe phosphonium salt precursor, and reexposed in the Ozalid copier atft./minute to produce an orange dye image in the newly exposed areas.The background regions are stabilized by heating to 110C for 5 seconds,producing a pale pink background. Other useful bases that can be used toliberate the phosphine and activate thecomposition include aqueoussolutions of an organic base such as those described in US. Pat. No.3,578,452.

Using techniques as described in Example 4, but coating aradiation-sensitive layer on each side of a transparent support whichhas a substantially colorless U.V. absorber contained in the support orin a separate layer or otherwise positioned between the support and oneof the radiation-sensitive layers, it is possible to form four-colorelements that can be viewed conveniently. Processing is as in Example 4,except that the appropriate exposures are desirably doubled to exposeseparately the radiation-sensitive materials present on each side of thesupport.

EXAMPLE 5 A coating solution is prepared from 0.15 g of 4-4-bis(azido)-3,3-dimethoxybiphenyl, 0.3 g of 2,3- naphthalenediol, 10drops of N,N,N, N-tetramethylethylenediamine, 3 drops of formaldehyde,15 ml of an 8.8 percent solution ofcopoly(N-isopropylacrylamideacrylamide-Z-acetoacetoxyethyl methacrylate)(Mole ratio 2:7:0.5) in a 1:1 by volume mixture of acetone and ethanol,and 15 ml of acetone. The mixture is doctor blade coated onpoly(ethylene terephthalate) film support at a wet thickness of 0.006inch and dried. A portion of the resultant element is dipped in a 10percent solution of cyclohexanon-3-yltriphenylphosphonium chloride inwater. The coating dipped portion is then dried, exposed at a setting of3 on a Model Brunning Copier, marketed by the Charles Bruning Division,Addressograph Multigraph Corporation, and heated at l 10C to stabilizethe winecolored dye image. The portion of the coating not dipped intothe phosphonium salt solution produces no image at all when exposed andheated in a like manner.

The invention has been described in detail with paraticular reference tocertain preferred embodiments thereof, but it will be understood thatvariations and modifications can be effected within the spirit and scopeof the invention.

There is claimed:

1. An image-forming composition comprising in admixture aradiation-sensitive organoazide which is one of either an aryl azide ora heterocyclyl azide and a triorganophosphine precursor which, ontreatment with base, liberates a triorganophosphine that can form aradiation-sensitive complex with the azide.

2. An image-forming composition as described in claim 1 and furthercomprising a polymeric binder material.

3. An image-forming element comprising a support having coated thereon alayer comprising an imageforming composition as described in claim 1.

4. An image-forming element as described in claim 3 and furthercomprising a binder material in said imageforming composition.

5. An image-forming composition comprising a radiation-sensitiveorganoazide which is one of eitherv an aryl azide or a heterocyclylazide and a triorganophosphine precursor which, on treatment with base,yields a triorganophosphine that can form a radiationsensitive complexwith the azide, the triorganophosphine that is yielded by said precursorbeing one that, when codissolved with p-morpholinophenylazide and- /or4-azidobenzenesulfonamide and a ,B-naphthol azodye-forming coupler,forms a composition which can be dried in a layer and imagewise exposedto activating radiation to form a photographic image, that, whenvisible, is different in color and/or intensity from the photographicimage that is formed when a similar composition, but without thetriorganophosphine, is dissolved, dried and exposed in the same manner.

6. An image-forming element comprising a support having coated thereon alayer comprising an image-

1. AN IMAGE-FORMING COMPOSITION COMPRISING IN ADMIXTURE ARADIATION-SENSITIVE ORGANOAZIDE WHICH IS INE OF EITHER AN ARYL AZIDE ORA HETEROCYCLYL AZIDE AND A TRIORGANOPHOSPHINE PRECURSOR WHICH, ONTREATMENT WITH BASE, LIBERATES A TRIORGANOPHOSPHINE THAT CAN BE FORM ARADIATION-SENSITIVE COMPLEX WITH THE AZIDE.
 2. An image-formingcomposition as described in claim 1 and further comprising a polymericbinder material.
 3. An image-forming element comprising a support havingcoated thereon a layer comprising an image-forming composition asdescribed in claim
 1. 4. An image-forming element as described in claim3 and further comprisinG a binder material in said image-formingcomposition.
 5. An image-forming composition comprising aradiation-sensitive organoazide which is one of either an aryl azide ora heterocyclyl azide and a triorganophosphine precursor which, ontreatment with base, yields a triorganophosphine that can form aradiation-sensitive complex with the azide, the triorganophosphine thatis yielded by said precursor being one that, when codissolved withp-morpholinophenylazide and/or 4-azidobenzenesulfonamide and a Beta-naphthol azodye-forming coupler, forms a composition which can be driedin a layer and imagewise exposed to activating radiation to form aphotographic image, that, when visible, is different in color and/orintensity from the photographic image that is formed when a similarcomposition, but without the triorganophosphine, is dissolved, dried andexposed in the same manner.
 6. An image-forming element comprising asupport having coated thereon a layer comprising an image-formingcomposition as described in claim 5.